Help, Rusted through fenders! - PeachParts Mercedes-Benz Forum

Apotheoun · #1 07-17-2008, 02:21 PM

Today I found several concealed pockets of rust and rusted through holes in the inner fenders of my '83 SD. The factory undercoating is failing. What are the best or most effective repair options? I don't much care how the repair looks, as long as it seals out weather, winter road salt and mud. I don't care if the repair needs renewing annually, either.

Garth

bgkast · #2 07-17-2008, 02:54 PM

Remove the damaged undercoating, clean and coat with POR-15

RAYMOND485 · #3 07-17-2008, 03:43 PM

1984 300d turbo 147k
Call "Phil"
1-888-333-4642
philip@peachparts.com
9AM-6PM ET

He can get any sheet metal you need.

bob_98sr5 · #4 07-17-2008, 05:37 PM

take a heat gun to it and remove the undercoating. use a cup brush on the end of a drill and remove all the surface rust. if the rust is crumbly and you can poke through it with a screwdriver, you need to cut it out. use a dremel if its not too big. if you dont have a welder, you can buy 20 gauge steel, cut out an overlapping patch, and then use epoxy glue to glue in a patch. scuff up the outside and then apply POR15 and then 3M undercoating. dont skimp on the undercoating

similarly, you can use POR15 with fiberglass then spray with undercoating.

read my blog in my sig for other tips

Apotheoun · #5 07-17-2008, 06:18 PM

Thanks for the quick response and guidance, everyone! Bob_98sr5, My God, what a comprehensive rebuild you are doing. Your blog is excellent as a resource! So far my '83 seems less rusty than your '87. At least I hope so! The front bottom edges of both rear fenders do have gaping one inch holes, though.

When you say "epoxy", what exactly do you mean? Where should I find and buy such an adhesive epoxy for auto body use?

I have some repair materials shopping to do. Thanks everyone!

I should clarify that the '84 SDS in the signature is now an '83 SD, since the accident. It looks the same but now is rebuilt with a whole replacement '83 body. The '83 body also has more rust underneath than the former '84. The mechanics, manual transmission, and interior are still from the '84.

Garth

bob_98sr5 · #6 07-20-2008, 08:58 PM

garth,

the restoration was a tough choice. i had the choice of painfully extracting some more money out of the seller (which i did) and take my time restoring/repairing all the rust issues or go through the hassle of sending it back minus shipping fees and a lawsuit and not have a car until the cross-border lawsuit could be settled. lawsuits are the devil, so we came to an amicable settlement over the phone.

epoxy glue: you can find it at just about any hardware store. if you are talking about the small metal piece of sheet metal i patched right underneath the driver's side well, yeah, i used epoxy glue. you will see if you go to home depot or the like that there's a brand called "loctite" (the same company that makes thread locker fluid) that sells different types of epoxy glue for different applications. remember, dont use this stuff on structural repairs, only repairs that are small and cosmetic.

Apotheoun · #7 07-21-2008, 11:12 PM

I already have a can of Eastwood Corroless, which seems to be the older nomenclature for their current product, Rust Encapsulator. I am reading that Corroless, and Rust encapsulator test very favorably, side by side with POR15, with evidence that the Eastwood formulation is even better at preventing rust creep. While it may not be as hard surfaced a coating as POR15, the Corroless may be more effective at actually stopping rust from returning. It seems I should give it a try.